The present invention relates to a cleaning apparatus and a cleaning method, by which objects to be processed, such as semiconductor wafers and glass substrates for a LCD (liquid crystal display) unit etc., are immersed and cleaned in chemical and subsequently dried.
For example, in a cleaning treatment of a manufacturing process for a semiconductor device, such as LSI etc., various cleaning apparatuses are employed for removing contaminants on the surfaces of the semiconductor wafers, such as particles, organic contaminants, metallic impurities and so on, and for etching surface of the wafer. Note, in this specification, the semiconductor wafer(s) will be called the wafer(s) for short, hereinafter. Above all, a cleaning apparatus of xe2x80x9cwetxe2x80x9d type comes into wide use on the grounds that the above contaminants can be removed effectively, etching can be done and a batch processing can be accomplished to enhance the throughput in the cleaning process.
In such a wet type of cleaning apparatus, the wafers to be cleaned are subjected to a chemical cleaning process (e.g. ammonia treatment, hydrogen fluoride treatment, sulfuric acid treatment etc.), a washing cleaning process using pure water etc., and a drying process using isopropyl alcohol [(CH3)2CHOH] or the like. Note, the isopropyl alcohol will be referred the IPA, hereinafter. Further, the cleaning apparatus is so constructed to supply the chemicals, the pure water and the IPA to processing baths in processing order and a drying room, respectively. Thus, with the above arrangement, a batch processing method where the wafer in blocks of e.g. 50 sheets are successively immersed in the processing baths and dried in the drying room, comes into wide use.
However, the provision of the processing baths and the drying room for each process causes the apparatus to be large-sized undesirably. In addition, because of a lot of opportunities for transporting the wafers in the apparatus, in other words, being exposed to atmosphere, there is a great possibility of the particles"" sticking to the wafers.
Therefore, in e.g. Japanese Unexamined Patent Publication (kokai) No. 64-81230 and the same No. 6-326073 etc., there are proposed cleaning apparatuses in each of which the processing baths and the drying room are formed in one body, so that the above-mentioned chemical process and drying process are carried out in one chamber. FIG. 1 shows one example of the cleaning apparatuses in the publications, representatively.
The shown cleaning apparatus comprises a chamber 200 and chemical (liquid) 202 stored in a lower portion 201 of the chamber 200. In processing, a wafer W is firstly immersed in the chemical 202. Thereafter, the wafer W is pulled up from the chemical 202 and then subjected to the drying process using the IPA etc. at an upper portion 203 of the chamber 200.
In the above-mentioned drying process while heating, however, there is a possibility that chemical atmosphere remaining in an upper area of the chamber 200 exerts a bad influence on the wafer W during the drying process. Furthermore, since there is a need to meet respective requirements of the chemical and drying processes simultaneously, the degree of freedom is restricted in design of the cleaning apparatus. Therefore, it is difficult to adopt various ideas to realize a high-speed cleaning process, a miniaturization of the chamber and so on. Meanwhile, in the drying process using the above IPA etc., it is generally executed to decompress the chamber by using a vacuum pump or the like. However, since the chamber in the cleaning apparatus constructed above, in which the chemical treatment etc. and the sequent drying process are executed together, has to have a large capacity volume to a certain extent, there are problems to be solved that it is necessary to increase a wall thickness of the chamber in order to ensure the pressure tightness and a high power vacuum pump is also required.
Accordingly, it is therefore an object of the present invention to provide a cleaning apparatus and a cleaning method, by which a object to be processed is not subjected to a bad influence from the chemical process during the drying process.
It is the other object of the present invention to provide a cleaning apparatus which has a high degree of freedom in design thereby to clean the objects rapidly and miniaturize the apparatus itself, and a cleaning method realized by using the cleaning apparatus.
It is the further object of the present invention to provide a cleaning apparatus which is capable of reducing a capacity of the chamber thereby to decrease a wall thickness of the chamber and an output required for the vacuum pump, and a cleaning method realized by using the cleaning apparatus.
It is the other object of the present invention to provide a cleaning apparatus and a cleaning method, by which it is possible to execute the drying process more effectively.
It is the other object of the present invention to provide a cleaning apparatus which is capable of preventing surfaces of the objects from being oxidized.
It is the other object of the present invention to provide a cleaning apparatus in which a processing bath and a drying section are separated from each other thereby to prevent mist etc. of treatment liquids from entering into a drying chamber thereby to accomplish a stable drying performance of the apparatus, and a cleaning method realized by using the cleaning apparatus.
As a first feature of the present invention, the above-mentioned objects described above can be accomplished by a cleaning apparatus comprising:
a processing bath for storing processing liquid in which the object is immersed;
a drying chamber arranged above the processing bath and provided with an opening which is disposed between a body of the drying chamber and the processing bath and through which the object is transported, the opening being capable of closing;
transporting means for transporting the object between the processing bath and the drying chamber through the opening; and
means for filling the drying chamber with an atmosphere of organic solvent.
Further, a second feature of the present invention resides in the cleaning apparatus in accordance with the first feature, wherein the opening further includes sealing means for sealing the drying chamber when the opening is closed.
As a third feature of the present invention, the above-mentioned objects described above can be also accomplished by a cleaning apparatus for cleaning a object to be processed, the apparatus comprising:
a processing bath for storing processing liquid in which the object is immersed;
a drying chamber arranged above the processing bath and provided with an opening which is disposed between a body of the drying chamber and the processing bath and through which the object is transported, the opening being capable of closing;
a retaining member for retaining the object;
a supporting member for supporting the retaining member from the drying chamber""s side, the supporting member being inserted into the processing bath through the opening in case of disposing the retaining member in the processing bath;
moving means for moving the object between the processing bath and the drying chamber by the supporting member;
first open and close means for opening and closing the opening, the first open and close means being constructed so as to seal the drying chamber at the first open and close means"" closing condition;
second open and close means for opening and closing the opening, the second open and close means being constructed so as to close the opening while leaving a clearance allowing the supporting member to pass there-through at the second open and close means"" closing condition; and
means for filling the drying chamber with an atmosphere of organic solvent.
As a fourth feature of the present invention, the above objects can be also accomplished by a cleaning apparatus for cleaning a object to be processed, the apparatus comprising:
a processing bath for storing processing liquid in which the object is immersed;
a drying chamber arranged above the processing bath and provided with an opening which is disposed between a body of the drying chamber and the processing bath and through which the object is transported, the opening being capable of closing;
a retaining member for retaining the object;
a supporting member for supporting the retaining member from the drying chamber""s side, the supporting member being inserted into the processing bath through the opening in case of disposing the retaining member in the processing bath;
moving means for moving the object between the processing bath and the drying chamber by the supporting member;
open and close means for opening and closing the opening, the open and close means being constructed so as to seal the drying chamber at a first closing mode of the open and close means and close the opening while leaving a clearance allowing the supporting member to pass there-through at a second closing mode of the open and close mean; and
means for filling the drying chamber with an atmosphere of organic solvent.
A fifth feature of the present invention resides in the cleaning apparatus in accordance with any one of the first feature to the fourth feature, wherein the processing liquid stored in the processing bath is a deaerated rinse.
A sixth feature of the present invention resides in the cleaning apparatus in accordance with the fifth feature, further comprising first blowing means arranged between the processing bath and the drying chamber, for blowing inert gas against the object transported from the processing bath to the drying chamber.
A seventh feature of the present invention resides in the cleaning apparatus in accordance with the sixth feature, further comprising cooling means for cooling the inert gas.
An eighth feature of the present invention resides in the cleaning apparatus in accordance with the seventh feature, further comprising:
decompressing means for decompressing the drying chamber; and
second blowing means for blowing the inert gas against the object in the drying chamber.
A ninth feature of the present invention resides in the cleaning apparatus in accordance with any one of the first feature to the fourth feature, further comprising heating means arranged in the drying chamber, for heating an interior of the drying chamber.
A tenth feature of the present invention resides in the cleaning apparatus in accordance with any one of the first feature to the fourth feature, wherein the processing liquid stored in the processing bath is a cooled rinse.
As an eleventh feature of the present invention, the above objects can be also accomplished by a cleaning method of cleaning a object to be processed, the cleaning method comprising the steps of:
(a) transporting the object from a drying chamber into a processing bath through a lower opening formed in the drying chamber while retaining the object by a retaining member supported on the drying chamber""s side;
(b) closing the lower opening;
(c) storing processing liquid in the processing bath before or after transporting the object from drying chamber into the processing bath and subsequent immersing the object in the processing liquid;
(d) opening the lower opening to transport the object from the processing bath into the drying chamber;
(e) closing the lower opening; and
(f) drying the object by an atmosphere of organic solvent in the drying chamber.
A twelfth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, further comprising a step of filling up the drying chamber with inert gas after the object has been transported from an outside of the cleaning apparatus into the drying chamber, the step preceding the step (b).
A thirteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, wherein inert gas is supplied into the processing bath in any one of the steps (a) to (f).
A fourteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, wherein gas containing organic solvent is supplied into the processing bath before the step (d).
A fifteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, wherein gas containing organic solvent is supplied into the processing bath before and during the step (d).
A sixteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, wherein, in the step (b), the lower opening is closed while leaving a clearance for allowing the object to be carried from the drying chamber""s side.
A seventeenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, wherein, in the step (e), the lower opening is closed to sealed up the drying chamber.
A eighteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature, further comprising a step of blowing inert gas against the object on transportation from the processing bath into the drying chamber.
An nineteenth feature of the present invention resides in the cleaning method in accordance with the eleventh feature or the seventeenth feature, after executing the step (f), further comprising a step of blowing inert gas against the object in the drying chamber while decompressing the drying chamber.
A twentieth feature of the present invention resides in the cleaning method in accordance with the eighteenth feature, between the steps (b) and (d), further comprising a step of filling the drying chamber with an atmosphere of organic solvent.
A twenty-first feature of the present invention resides in the cleaning method in accordance with the nineteenth feature, the processing liquid stored in the processing bath is a cooled rinse.
According to the first feature of the invention, since the drying chamber and the processing bath are separated from each other up and down while a space of the drying chamber can be insulated from a space of the processing bath through the closing opening, the object has no possibility to receive a bad influence from the chemical treatment during the drying process. In addition, since the arrangement allows the drying chamber and the processing bath to be designed under respective conditions independent of each other, it is possible to optimize the cleaning process and further miniaturize the cleaning apparatus because of the enhanced degree of freedom in the process design. Moreover, since the above-mentioned arrangement allows the volume of the drying chamber to be reduced, it is possible to reduce the wall thickness of the drying chamber and the processing bath when it is required to decompress the drying chamber while filling up with the atmosphere of the organic solvent. In addition, it is possible to make the decompression with a low-powered vacuum pump.
According to the second feature to the fourth feature of the invention, since the arrangement allows the interior of the drying chamber to be further sealed up, it is possible to reduce the wall thickness of the drying chamber and reduce the power of the vacuum pump required for the decompression.
According to the fifth feature of the invention, since the processing liquid stored in the processing bath is the deaerated rinse, it is possible to prevent the surface of the object from being oxidized.
According to the sixth feature of the invention, since the blowing means for blowing the inert gas against the object on transportation from the processing bath to the drying chamber also serves to dry the object, the drying process can be accomplished more effectively. Further, according to the seventh feature, owing to the cooled inert gas, it is possible to promote the condensation of organic solvent in the drying chamber.
According to the eighth feature of the present invention, since the inert gas is blown against the object in the drying chamber while decompressing the drying chamber, it is possible to dry the object more effectively.
According to the ninth feature of the present invention, as the temperature of the drying chamber can be elevated by the panel heater, it is possible to dry the object more effectively.
Further, according to the tenth feature, owing to the use of the cooled rinse, it is possible to promote the condensation of organic solvent in the drying chamber.
According to the eleventh feature of the invention, after the object has been transported from the processing bath to the drying chamber, the opening is then closed to shelter the space and thereafter, the object is subjected to the drying process. Thus, the object has no possibility to receive a bad influence from the chemical treatment during the drying process. Further, since the forthcoming process in the next processing bath can be prepared while the drying process is executed, it is possible to improve throughput of the cleaning apparatus. Additionally, since the arrangement allows the drying chamber and the processing bath to be designed under respective conditions independent of each other, it is possible to optimize the cleaning process and further miniaturize the cleaning apparatus because of the enhanced degree of freedom in the process design. Moreover, since the above-mentioned arrangement allows the volume of the drying chamber to be reduced, it is possible to reduce the wall thickness of the drying chamber and the processing bath when it is required to decompress the drying chamber while filling up with the atmosphere of the organic solvent. In addition, it is possible to make the decompression with the low-powered vacuum pump.
According to the twelfth and thirteenth features of the invention, since the drying chamber and the processing bath can be filled up with the atmosphere of the inert gas early or throughout the whole processes, it is possible to prevent the object from being oxidized.
According to the fourteenth and fifteenth feature of the invention, when the object to be processed enters into the drying chamber, the water on the object is removed to some extent. Moreover the rest of water on the object is easily replaced with organic solvent. Accordingly, it is possible to carry out the drying process more effectively.
According to the sixteenth and seventeenth features of the invention, it is possible to separate the drying chamber from the processing bath more clearly. Thus, the object has no possibility to receive a bad influence from the chemical treatment during the drying process. Additionally, since the arrangement allows the drying chamber and the processing bath to be designed under respective conditions independent of each other, it is possible to carry out the cleaning process rapidly and further miniaturize the cleaning apparatus because of the enhanced degree of freedom in the process design.
According to the eighteenth and nineteenth features of the invention, since the arrangement allows the interior of the drying chamber to be further sealed up, it is possible to reduce the wall thickness of the drying chamber and reduce the power of the vacuum pump required for the decompression.
According to the twentieth feature of the invention, since the drying chamber has been already filled up with the atmosphere of organic solvent before transporting the object into the drying chamber, it is possible to carry out the drying process more effectively.
Further, according to the twenty-first feature, owing to the use of the cooled rinse, it is possible to promote the condensation of organic solvent in the drying chamber.
The above and other features and advantages of this invention will become apparent, and the invention itself will best be understood, from a study of the following description and appended claims, with reference had to the attached drawings showing a preferred embodiment of the invention.